1. Technical Field
The present disclosure relates to a testing system, and more particularly to a testing system for testing conversion efficiency of a power supply.
2. Description of Related Art
A typical testing system for testing conversion efficiency of a power supply unit (PSU) includes an AC source applied to the PSU, a power meter, a first multimeter, a second multimeter, a first rotary switch, a second rotary switch, a third rotary switch, and a DC electronic load. The switches S1, S2, S3 are one pole multi-way switches. The power meter is connected between the AC source and the PSU for measuring AC input power to the PSU. The PSU output power rails include: 12V, 12 VCPU (a power rail for CPU), 5V, 3.3V, −12V, and 5 Vaux (standby voltage of 5V). Each of the power rails' output from the PSU is supplied to the DC electronic load via a resistor. The first rotary switch can be switched from one conducting position to another. Thus, the first multimeter is capable of connecting to each of the power rails and measuring an effective output voltage of each of the power rails. The second and third rotary switches can be switched from one conduction position to another for connecting the second multimeter to each of the resistors in a parallel connection. Thus, an output current of each of the power rails can be calculated using the formula: I=U/R. An output power of each of the power rails can be calculated by the formula: P=UI. A total output power of the PSU equals the sum of all the output power of the power rails. The ratio of the total output power of the PSU to the AC input power can be calculated to determine whether the PSU achieves a standard conversion efficiency.
However, the typical testing system needs an operator to manually turn the rotary switches and record the current and voltage of each of the power rails, which is inefficient.